initial commit: The OrbTK book source tree

All files have a strong relation to the book sources of the
rust-lang project itself. This may help to lower the burden
for intrested people to get involved in OrbTK as well as
reuse workflow habits.

* LICENSE-MIT: The projekt licensing terms
* README.md: Github frontpage
* CONTIRBUTING.md: Advises on howto help improving the book
* style-guide.md: Advises on howto improve the readability of
  generated prose and code.
* tools: layout helper scripts and rust-code
* ci: continius integration helper scripts
* .gitattributes: set git default behaviours
* .gitignore: keep source tree sane
* Cargo.toml: package dependencies
* rustfmt.toml: formatting rules for rust code
* book.toml: mdBook dependencies

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>

ci/validate.sh

@@ -0,0 +1,4 @@
+for file in src/*.md ; do
+    echo Checking references in $file
+    cargo run --quiet --bin link2print < $file > /dev/null
+done